[Python-3000] PEP 3131 - the details (original) (raw)

Hernan Martínez-Foffani hernan at foffani.org
Thu May 17 11:35:19 CEST 2007

> > The same as in .NET (and hence IronPython)? > > This kind of research is time consuming; it cost me an hour to come > up with above list. Please research it for yourself.

C# identifiers (cont) About normalization and @

                                    Paragraph 2 (Page 56, Line 5)

1 An identifier in a conforming program must be in the canonical format defined by Unicode Normalization Form C, as defined by Unicode Standard Annex 15. 2 The behavior when encountering an identifier not in Normalization Form C is implementation-defined; however, a diagnostic is not required.

                                    Paragraph 3 (Page 56, Line 8)

1 The prefix "@" enables the use of keywords as identifiers, which is useful when interfacing with other programming languages. 2 The character @ is not actually part of the identifier, so the identifier might be seen in other languages as a normal identifier, without the prefix. 3 An identifier with an @ prefix is called a verbatim identifier. [Note: Use of the @ prefix for identifiers that are not keywords is permitted, but strongly discouraged as a matter of style. end note] [Example: The example:

class @class { public static void @static(bool @bool) { if (@bool) System.Console.WriteLine("true"); else System.Console.WriteLine("false"); } } class Class1 { static void M() { cl\u0061ss.st\u0061tic(true); } }

defines a class named "class" with a static method named "static" that takes a parameter named "bool". Note that since Unicode escapes are not permitted in keywords, the token "cl\u0061ss" is an identifier, and is the same identifier as "@class". end example]

                                   Paragraph 4 (Page 56, Line 32)

1 Two identifiers are considered the same if they are identical after the following transformations are applied, in order:

* 2 The prefix "@", if used, is removed.
* 3 Each unicode-escape-sequence is transformed into its

corresponding Unicode character. * 4 Any formatting-characters are removed.

                                   Paragraph 5 (Page 56, Line 37)

1 Identifiers containing two consecutive underscore characters (U+005F) are reserved for use by the implementation; however, no diagnostic is required if such an identifier is defined. [Note: For example, an implementation might provide extended keywords that begin with two underscores. end note]

Same disclaimer as before applies.

Regards, -Hernán.

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